Radek Ošlejšek

Hybrid Approach to Sonification of Color Images

This paper deals with the accessibility of graphics for visually impaired people. It presents a novel method of sonification of complex graphical objects, such as color photographs, based on a hybrid approach combining sound and speech communication. This approach is supported by a special color model, called semantic color model, which is introduced in the paper. The semantic color model possesses suitable properties that can be used to deliver the relevant graphical information in sound or speech in a convenient form. The integration of this approach with the annotated SVG format developed within the ongoing GATE project, which is also briefly described in the paper, enhances the efficiency of the system.

GATE to Accessibility of Computer Graphics

This paper presents a framework for integrating current information technologies into a platform enabling the blind and visually impaired people to access computer graphics based on the annotated SVG format. We also present a technique enabling the conversion of any graphical object to the annotated SVG format and easy annotation supported by OWL based ontology. This approach is not limited to vector graphics only, but enables also the flexible annotation and application of raster graphics (e.g. photographs). We briefly describe the architecture of the GATE (Graphics Accessible To Everyone) project, which contains the corresponding implemented modules. As an illustration, we provide an example showing how the blind can access the annotated graphics.

Creating pictures by dialogue

This paper deals with the problem of generating a picture of a scene by means of describing it in the terms of natural language ontologies. The corresponding graphical format, being formally represented in the form of the Pawlak information system, involves a full semantic description of the picture. Therefore, the pictures generated in this way “blind-friendly”, i.e. they can be automatically fully described. A simple example of such a picture generation is presented here

A flexible, low-level scene graph traversal with explorers

We introduce a novel design architecture for scene graph based applications. A model is based on GoF design patterns with respect to reusability and maintenance. With integration of patterns into the construction of a scene graph, the scenes description can be easily extended by new features, as new types of scene graph attributes, spatial data structures and geometries. The proposed model supports efficient traversal of a scene graph based on unified interfaces of scene graph nodes. It offers generic yet sufficiently low-level framework usable by a wide range of various rendering strategies.

Reliability analysis in component-based development via probabilistic model checking

Engineering of highly reliable systems requires support of sophisticated design methods allowing software architects to competently decide between various design alternatives already early in the development process. Architecture-based reliability prediction provides such capability. The formalisms and analytical methods employed by existing approaches are however often limited to a single reliability measure (the probability of failure on demand) and consideration of behavioural uncertainty (focusing on the uncertainty in model parameters, not the behaviour itself). This paper presents a formal reliability assessment approach for component-based systems based on the probabilistic model checking of various reliability-related properties specified in probabilistic linear temporal logic (PLTL). The systems are formalized as Markov decision processes (MDP), which allows software architects to encode behavioural uncertainties into the models in terms of nondeterministic (scheduler-decided) choices in the MDP.

Generic graphics architecture

We introduce a generic architecture that is sufficiently general to treat a wide variety of rendering strategies. The architecture is particularized according to common features of energy distribution techniques. The survey of energy distribution techniques and the principles used by various illumination algorithms are discussed in the context of possible solutions in an object-oriented generic rendering architecture.

KYPO Cyber Range: Design and Use Cases

The physical and cyber worlds are increasingly intertwined and exposed to cyber attacks. The KYPO cyber range provides complex cyber systems and networks in a virtualized, fully controlled and monitored environment. Time-efficient and cost-effective deployment is feasible using cloud resources instead of a dedicated hardware infrastructure. This paper describes the design decisions made during it’s development. We prepared a set of use cases to evaluate the proposed design decisions and to demonstrate the key features of the KYPO cyber range. It was especially cyber training sessions and exercises with hundreds of participants which provided invaluable feedback for KYPO platform development.

VRECKO: Virtual Reality Framework

In this paper, we present a framework for experimenting with virtual environments. The architecture of the system VRECKO is designed for the rapid prototyping of techniques for human-computer interaction. The architecture is flexible, but simple. Virtual environment entities and other components can be configured at run time. We demonstrate the flexibility of the approach on several examples of experiments and tools which were realized in VRECKO.

Is Accessibility an Issue in the Knowledge Society? Modern Web Applications in the Light of Accessibility

Recent development in Web shows a significant trend towards more user participation, massive use of new devices including portables, and high interactivity. The user participation goes hand in hand with inclusion of all potential user groups — also with special needs. However, we claim that albeit all the effort towards accessibility, it has not yet found an appopriate reflection among stakeholders of the “Top Web Applications” nor their users. This leads to undesired causes — the business-driven Web without all user participation is not a really democratic medium and, actually, does not comply with the original characteristics of Web 2.0. The paper tries to identify perspectives of further development including standardization processes and technical obstacles behind. It also shows ways and techniques to cope with the challenge based on our own research and development in accessible graphics and dialog-based systems.

Visual Analytics for Network Security and Critical Infrastructures

A comprehensive analysis of cyber attacks is important for better understanding of their nature and their origin. Providing a sufficient insight into such a vast amount of diverse (and sometimes seemingly unrelated) data is a task that is suitable neither for humans nor for fully automated algorithms alone. Not only a combination of the two approaches but also a continuous reasoning process that is capable of generating a sufficient knowledge base is indispensable for a better understanding of the events. Our research is focused on designing new exploratory methods and interactive visualizations in the context of network security. The knowledge generation loop is important for its ability to help analysts to refine the nature of the processes that continuously occur and to offer them a better insight into the network security related events. In this paper, we formulate the research questions that relate to the proposed solution.